Performance of existing definitions and tests for the diagnosis of invasive aspergillosis in critically ill, adult patients: A systematic review with qualitative evidence synthesis

OBJECTIVES

To summarize the available evidence on the diagnostic performance for invasive aspergillosis (IA) in non-hematological, non-solid organ transplantation critically ill patients of the following: (i) existing definitions of IA (developed either for classical immunocompromised populations or for non-immunocompromised critically ill patients); (ii) laboratory tests; (iii) radiology tests.

METHODS

A systematic review was performed by evaluating studies assessing the diagnostic performance for IA of a definition/s and/or laboratory/radiology test/s vs. a reference standard (histology) or a reference definition.

RESULTS

Sufficient data for evaluating the performance of existing definitions and laboratory tests for the diagnosis of IA in critically ill patients is available only for invasive pulmonary aspergillosis. Against histology/autopsy as reference, the AspICU definition showed a promising diagnostic performance but based on small samples and applicable only to patients with positive respiratory cultures. Studies on laboratory tests consistently indicated a better diagnostic performance of bronchoalveolar lavage fluid (BALF) galactomannan (GM) than serum GM, and a suboptimal specificity of BALF and serum (1,3)-β-D-glucan.

CONCLUSIONS

Evidence stemming from this systematic review will guide the discussion for defining invasive aspergillosis within the FUNDICU project. The project aims to develop a standard set of definitions for invasive fungal diseases in critically ill, adult patients.

The impact of rifaximin in the prevention of bacterial infections in cirrhosis

OBJECTIVE

Bacterial infections are a leading factor in the progression from compensated to decompensated cirrhosis, with consequent worsening of the prognosis, and concerted efforts have been made to reduce infections and improve the survival rate of these patients. We retrospectively investigated the rate of infections in hospitalized cirrhotic patients under treatment with rifaximin.

PATIENTS AND METHODS

We enrolled 649 patients whose clinical and personal data, prescribed therapy, microbiological findings and laboratory tests were collected from previous discharge letters and our institution database. The efficacy of rifaximin in preventing several types infection was evaluated by comparing outcomes for rifaximin-treated patients vs patients receiving no antibiotic treatment.

RESULTS

The risk of developing selected bacterial infections was significantly lower in patients treated with rifaximin (OR 0.29; 95% CI 0.20-0.40, p < 0.001).

CONCLUSIONS

Continuous treatment with rifaximin may prevent bacterial infections in cirrhotic patients.

General issues on microbial translocation in HIV-infected patients

The lumen of the gastrointestinal tract is home to an enormous quantity of different bacterial species that thrive in an often symbiotic relationship with the host. It is the principal source of microbial products because of its massive bacterial load. Injury to the immune component of the gastrointestinal mucosal surface, along with damage to the intestinal epithelial microenvironment with its antimicrobial functions, may affect systemic immune activation during the chronic phase of HIV infection through the increased translocation of luminal microbial products. Moreover, microbial translocation, which is defined as "the passage of both viable and nonviable microbes and microbial products such as endotoxin across anatomically intact intestinal barrier", may be a fundamental mechanism through which HIV accelerates progression of chronic viral hepatitis. Improvements in the tools available to microbiota research, and especially advancement of our knowledge in this area may help us in controlling the evolution of HIV disease, although population complexity and diversity between individuals make this challenging.